In recent years, a display mounted with an organic EL panel has been proposed in association with wide spread use of a thin display. The organic EL panel is liable to cause problems such as ambient light reflection and background reflection because the panel includes a metal layer having high reflectivity. In view of the foregoing, it has been known that those problems are prevented by providing a circularly polarizing plate including a λ/4 plate on a viewer side. However, a circularly polarizing plate using an ordinary λ/4 plate involves a serious problem of decoloring. The use of a combination of a λ/4 plate and a λ/2 plate (Patent Literature 1), and the use of a λ/4 plate constituted of the so-called reverse wavelength dispersion material (Patent Literature 2) have each been proposed as means for solving such problem.
Here, when a circularly polarizing plate is used in an organic EL panel, the circularly polarizing plate is preferably as thin as possible in consideration of a demand for the thinning of the organic EL panel, and hence the use of a combination of a λ/4 plate and a λ/2 plate like the technology of Patent Literature 1 is required to be avoided to the extent possible. The use of only a λ/4 plate constituted of the reverse wavelength dispersion material like the technology of Patent Literature 2 can meet the demand for the thinning of the organic EL panel. However, the organic EL panel employing the technology of Patent Literature 2 involves a problem in that the warping of the panel itself occurs, and as a result, reflection unevenness occurs.